Home climate and habitat drive ecotypic stress response differences in an invasive grass. Issue 6 (24th November 2020)

• Record Type: Journal Article
• Authors: Lakoba, Vasiliy T; Barney, Jacob N
• Editors: Picó, Xavier
• Is Part Of: AoB plants. Volume 12:Issue 6(2020)
• Publication Date: 2020-11-24
• Subjects: Agricultural weeds -- climate adaptation -- ecotype -- invasive plants -- plant stress -- rapid adaptation; Plants -- Periodicals; Botany -- Periodicals; 580.5
• DOI: 10.1093/aobpla/plaa062
• Languages: English
• ISSNs: 2041-2851

Abstract

Abstract: Invasive plants and agricultural weeds are a ubiquitous and ever-expanding threat to biosecurity, biodiversity and ecosystem services. Many of these species are known to succeed through rapid adaptation to biotic and abiotic stress regimes, often in highly disturbed systems. Given the current state of evidence for selection of weedy genotypes via primary physiological stresses like drought, flooding, heat, cold and nutrient deficiency, we posit that adaptation to land management regimes which comprise suites of these stresses can also be expected. To establish this link, we tested adaptation to water and nutrient stresses in five non-agricultural and five agricultural populations of the invader Johnsongrass ( Sorghum halepense ) sampled across a broad range of climates in the USA. We subjected seedlings from each population to factorial drought and nutrient stresses in a common garden greenhouse experiment. Agricultural and non-agricultural ecotypes did not respond differently to experimentally applied stresses. However, non-agricultural populations from more drought-prone and nutrient-poor locations outperformed their agricultural counterparts in shoot allocation and chlorophyll production, respectively. We also found evidence for root allocation adaptation to hotter climates, in line with other C4 grasses, while greater adaptation to drought treatment was associated with soil organic carbon (SOC)-rich habitats. These findings imply that adaptation to land-use types can interact with other macrohabitat parameters, which will be fluctuating in a changing climate and resource-needy world. We see that invasive plants are poised to take on novel habitats within their introduced ranges, leading to complications in the prevention and management of their spread. Abstract : Johnsongrass, a perennial invader on six continents, is established in both agricultural and non-agricultural habitats across the USA. By testing drought and nutrient stress response of seedlings from populations across the US range, we found that precipitation and soil fertility from the site of population origin mediated drought adaptation, while the latter also impacted differential chlorophyll content of agricultural and non-agricultural ecotypes. Our findings suggest simultaneous rapid adaptation to climate, soil fertility and land use in the establishment of this invasive species. Notably, the non-agricultural ecotype, which emerged after intensive management in cropland, showed greater adaptation to nutrient-poor soils.